Identification of differentially expressed RNAs of lung cancer cells.
ABSTRACT: Twist1 induces cancer metastasis. Identification of Twist1 downstream targets should help to delineate the mechanisms of Twist1-induced cancer metastasis. Expression profiles of H1299 control cells vs. H1299 with knockdown of Twist1 were compared to identify Twist1 downstream targets.
Project description:Colorectal carcinoma (CRC) is one of the most common cancers worldwide. Re-evaluating our current knowledge on CRC and developing novel therapeutic strategies is still crucial. Accumulating evidence suggests that cancer cells possess characters reminiscent of those of normal stem cells. Unveiling small RNAs responsible for cell stemness and chemoradioresistance should eventually lead to the development of novel therapeutic approaches. Expression profiles of parental CRC cells and cancer spheres expanded under stem cell medium cultivation were generated for identifying key regulators.
Project description:In order to explore the status of DNA methylation in hypoxia response, we show that TET1, a DNA dioxygenase converting 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), regulates hypoxia-responsive gene expression. Hypoxia/HIF-2α regulates the expression of TET1. Knockdown of TET1 mitigated hypoxia-induced EMT. RNA sequencing and 5hmC sequencing identified the set of TET1-regulated genes. Four samples (Four samples, Hypoxia (scrambled control), Hypoxia (TET1-si), Normoxia (scrambled control) and Normoxia (TET1-si), are performed by RNA-Seq and hMeDIP-Seq RNA-Seq and hMeDIP-Seq
Project description:Recent studies including next-generation sequencing have identified genomic events in prostate cancer including ETS gene fusions. However, it is critical to identify druggable targets for prostate cancer and their mechanism of action for therapeutic intervention. Here, we show that prolyl 4-hydroxylase, alpha polypeptide I (P4HA1) is overexpressed in aggressive prostate cancer and amplified in a subset of metastatic prostate cancer. This study provides mechanistic insights of P4HA1 regulation and its mode of action including its role in regulating MMP1. Importantly, P4HA1 mediated invasion in cancer cells could be reversed using MMP1 inhibitor, revealing therapeutic utility of targeting P4HA1 either directly or by inhibiting its downstream effectors. Two-color experiment, in duplicates.
Project description:Men who develop metastatic castration-resistant prostate cancer (CRPC) invariably succumb to the disease. The development and progression to CRPC following androgen ablation therapy is predominantly driven by unregulated androgen receptor (AR) signaling1-3. Despite the success of recently approved therapies targeting AR signaling such as abiraterone4-6 and second generation anti-androgens MDV3100 (enzalutamide)7,8, durable responses are limited, presumably due to acquired resistance. Recently JQ1 and I-BET, two selective small molecule inhibitors that target the amino-terminal bromodomains of BRD4, have been shown to exhibit antiproliferative effects in a range of malignancies9-12. Here we show that AR signaling-competent CRPC cell lines are preferentially sensitive to BET bromodomain inhibition. BRD4 physically interacts with the N-terminal domain of AR and can be disrupted by JQ111,13. Like the direct AR antagonist, MDV3100, JQ1 disrupted AR recruitment to target gene loci. In contrast to MDV3100, JQ1 functions downstream of AR, and more potently abrogated BRD4 localization to AR target loci and AR mediated gene transcription including induction of TMPRSS2-ERG and its oncogenic activity. In vivo, BET bromodomain inhibition was more efficacious than direct AR antagonism in CRPC xenograft models. Taken together, these studies provide a novel epigenetic approach for the concerted blockade of oncogenic drivers in advanced prostate cancer. Two-color experiment, in duplicates
Project description:Twist1 is a transcription factor that induces EMT and drives metastasis in prostate cancer. We examined global gene expression in Myc-CaP mouse prostate cancer cells following overexpression of Twist1 and the Twist1 mutants F191G, AQA, and DQD. 15 total samples were analysed, with 3 replicates of 5 groups: Twist1-WT, Twist1-AQA, Twist1-DQD, Twist1-F191G, and vector control. We performed the comparisons: WT > VEC, F191G > VEC. Samples were normalized by Twist1 expression in addition to normal
Project description:In the present study, we used a high-throughput small RNA deep sequencing followed by a systematic computational analysis to identify genome wide mutant p53R273H regulated miRNAs in both DNA damage dependent and independent context. Several miRNA-mRNA regulatory networks have been predicted that might contribute to mutant p53 GOF properties. Differentially regulated miRNA signature profile has been validated in the lung cancer patients harboring wildtype and mutant p53. We identified specific miRNA signatures for lymph node metastasis associated with p53 mutation in lung adenocarcinoma and also predicted the possible contribution of two mutant p53 regulated miRNAs in EMT process. Furthermore, this study identified a hitherto unknown miRNA in human which might act as one of the crucial downstream targets of GOF mutant p53 to confer oncogenic properties. Determination of mutant p53R273H regulated microRNAs H1299 cells.
Project description:Numerous epithelial-to-mesenchymal transition (EMT)-promoting transcription factors have been implicated in tumorigenesis or metastasis, as well as chemoresistance of cancer. However, the underlying mechanism mediating these processes is unclear. Here we report that Foxq1, a forkhead box-containing transcription factor and EMT-inducing gene, promotes stemness traits and chemoresistance in mammary epithelial cells. We identify Twist1, Zeb2, and PDGFRα and β as Foxq1 downstream targets using an expression profiling assay. Further studies reveal that PDGFRα and β can be directly regulated by Foxq1, or indirectly through Twist1. Knockdown of both PDGFRα and β shows more significant effects on reversing Foxq1-promoted oncogenesis in vitro and in vivo than knockdown by either PDGFRα or β alone. PDGFRβ, but not PDGFRα, shows potent effects in reversing Foxq1-promoted stemness traits. Moreover, pharmacological inhibition or gene silencing of PDGFRs sensitize mammary epithelial cells to chemotherapeutic agents in vitro and in vivo. These findings collectively indicate PDGFRs as critical mediators underlying breast cancer tumorigenesis and chemoresistance driven by EMT promoting genes, which have potential clinical implications for cancer therapy. The purpose of these experiments is to investigate the downstream targets of several transcriptional factors including Foxq1 and IRX5. Another purpose is to compare the expression pattern between basal-like breast cancer cells including MDA-MB231, SUM159 and SUM1315.
Project description:Malformations of the cardiovascular system are the most common type of birth defect in humans, affecting predominantly the formation of valves and septa. During heart valve and septa formation, cells from the atrio-ventricular canal (AVC) and outflow tract (OFT) regions of the heart undergo an epithelial-to-mesenchymal transformation (EMT) and invade the underlying extracellular matrix to give rise to endocardial cushions. Subsequent maturation of newly formed mesenchyme cells leads to thin stress-resistant leaflets. TWIST1 is a basic helix-loop-helix transcription factor expressed in newly formed mesenchyme cells of the AVC and OFT that has been shown to play roles in cell survival, cell proliferation and differentiation. However, the role and downstream targets of TWIST1 during heart valve formation remain unclear. To identify genes important for heart valve development downstream of Twist1 we performed global gene expression profiling of AVC, OFT, atria and ventricles of the embryonic day 10.5 mouse heart by tag-sequencing (Tag-seq). Using this resource we identified a novel set of 1246 genes, including 201 regulators of transcription, enriched in the valve forming regions of the heart. We compared these genes to a Tag-seq library from the Twist1 null developing valves revealing significant gene expression changes. These changes were consistent with a role of TWIST1 in controlling differentiation of mesenchymal cells following their transformation from endothelium in the mouse. To study the role of TWIST1 at the DNA level we performed chromatin immunoprecipitation and identified novel direct targets of TWIST1 in the developing heart valves. Our findings are consistent with a role for TWIST1 in the differentiation of AVC mesenchyme post-EMT in the mouse, and suggest that TWIST1 exerts its function by direct DNA binding to activate valve specific gene expression. Profiled the AVC, OFT, atria and ventricles of the embryonic day 10.5 mouse heart by tag-sequencing (Tag-seq) (no replicates). We also produced a Tag-seq library from Twist1 null developing valves to reveal the gene expression changes associated with loss of this gene.
Project description:Twist1, a basic helix-loop-helix transcription factor, is expressed in mesenchymal precursor populations during embryogenesis and in metastatic cancer cells. In the developing heart, Twist1 is highly expressed in endocardial cushion (ECC) valve mesenchymal cells and is down regulated during valve differentiation and remodeling. Previous studies demonstrated that Twist1 promotes cell proliferation, migration, and expression of primitive ECM molecules in ECC mesenchymal cells. Furthermore, Twist1 expression is induced in human pediatric and adult diseased heart valves. However, the Twist1 downstream target genes that mediate increased cell proliferation and migration during early heart valve development remain largely unknown. Candidate gene and global gene profiling approaches were used to identify direct transcriptional targets of Twist1 during heart valve development. Candidate target genes were analyzed for evolutionarily conserved regions (ECRs) containing E-box consensus sequences that are potential Twist1 binding sequences. ECRs containing conserved E-box sequences were identified for Twist1 responsive genes Tbx20, Cdh11, Sema3C, Rab39b, and Gadd45a. Twist1 binding to these sequences in vivo was determined by chromatin immunoprecipitation assays, and binding was detected in ECCs but not late stage remodeling valves. In addition identified Twist1 target genes are highly expressed in ECCs and have reduced expression during heart valve remodeling in vivo which is consistent with the expression pattern of Twist1. Together these analyses identify multiple new genes involved in cell proliferation and migration that are differentially expressed in the developing heart valves, are responsive to Twist1 transcriptional function, and contain Twist1 responsive regulatory sequences. Murine MC3T3-E1 preosteoblast cells were treated with siScrambled control or siTwist1 to achieve knockdown of Twist1. Both siScr and siTwist1 were performed in triplicate. Isolated RNA was analyzed with Affymetrix muring MOE 430 2.0 gene chip microarray.
Project description:Posttranslational histone modifications play important roles in regulating chromatin structure and function. Histone H2B ubiquitination and deubiquitination have been implicated in transcriptional regulation, but the function of H2B deubiquitination is not well defined, particularly in higher eukaryotes. Here we report the purification of USP49 as a histone H2B specific deubiquitinase and demonstrate that H2B deubiquitination by USP49 is required for efficient co-transcriptional splicing of a large set of exons. USP49 forms a complex with RVB1 and SUG1, and specifically deubiquitinates histone H2B in vitro and in vivo. USP49 knockdown results in small changes in gene expression, but affects the abundance of over 9,000 isoforms. Exons down-regulated in USP49 knockdown cells show both elevated levels of alternative splicing and a general decrease in splicing efficiency. Importantly, USP49 is relatively enriched at this set of exons. USP49 knockdown increased uH2B levels at these exons as well as upstream 3’ and downstream 5’ intronic splicing elements. Change in H2B ubiquitination level, as modulated by USP49, regulates U1A and U2B association with chromatin and binding to nascent pre-mRNA. Although H3 levels are relatively stable after USP49 depletion, H2B levels at these exons are dramatically increased, suggesting that uH2B may enhance nucleosome stability. Therefore, this study identifies USP49 as a histone H2B specific deubiquitinase and uncovers a critical role for H2B deubiquitination in co-transcriptional pre-mRNA processing events. Examination of gene expression in wild type and USP49 knockdown cells [RNA-Seq]